1. Field of the Invention
The present invention relates, in general, to fittings and connectors for attaching electrical conductors to electrical devices and, specifically, to fittings and connectors for attaching electrical conductors to hand held bar code scanners.
2. State of the Art
In multi-conductor cords, small wires within the sheath or cord are subject to breakage after continual bending at a sharp radius which usually occurs at the connection of the cord to an electrical device. Hand held electrical devices, such as drills, and home appliances, such as hair dryers, etc., require extensive cord maintenance since such devices are manipulated through various angles and orientations during their use which puts considerable stress on the point of connection between the electrical conductor and the device.
In the electronics industry, portable hand held, moving beam, bar code scanners are used to read the bar code label on packages, objects, etc. Such scanners are extensively manipulated by a user in order to properly position the read head of the scanner to perform its optical function of reading the bar code label. Since the electrical conductor is stationarily attached at one end to a terminal, computer, etc., any bending movement of the scanner results in a bend at the point of connection of the electrical conductor or cord to the scanner.
With the advent of surface mount technology, the microchips employed in bar code scanners have reached a functional density to permit internal processing of the data (versus an external data decoder processing) within the scanner itself. Furthermore, such technology enables the scanner to directly transmit such data to a host computer. The electrical cords employed with such hand held scanners may have a range of internal conductors between three and twenty separate wires, depending upon the host interface requirements. As the cable has a fixed exterior physical diameter for its connection to the scanner, utilizing higher numbers of wires within the cable or cord requires a smaller gauge or wire size of the internal wires. These small gauge wires have a higher tendency to break after repeated bending coupled with a stretching action which is typically employed with hand held bar code scanners.
Such breakage renders the bar code scanner inoperable and thus requires immediate cable repair or replacement of the entire scanner and cable. Due to the high cost of such bar code scanners, having many spare scanners for replacement becomes quite costly. Furthermore, intermittent electrical signals due to cable degradation or wear causes many problems in a commercial environment where accurate data is critical to high productivity. Such gradual degradation also makes it difficult to identify data loss being due solely to cable malfunction.
In the general electrical arts, various connectors have been devised to attach an electrical conductor to an electrical device. Such connectors permit movement of the device and the electrical conductor with respect to each other, typically to provide repositioning of the electrical device. Such connectors employ ball and socket connections and other rotatable fittings to permit such rotation between the connector, the electrical conductor passing therethrough, and the electrical device. However, such connectors have a limited degree of rotation for fixed applications, such as lamps, and have not been applied to hand held, portable electrical devices for strain relief purposes. Nor have such rotatable or swivel connectors been employed with hand held, bar code scanners. Further, such previously devised rotatable connectors for electrical devices have fixed connections, such as threaded fasteners, at opposed ends for interconnection with the electrical device or a rigid tube surrounding the conductor which forms a part of the device, such as a lamp stand. In such connectors, the degree of rotation of the connectors merely provide for stationary repositioning of the electrical device with respect to the other components of the device, such as the rigid conductor tube.
Strain reliefs have been provided for electrical conductors at the point of connection of the conductors to an electrical device, such as hand held appliances, power tools, etc. Such strain reliefs comprise a somewhat rigid sheath which prevents the formation of sharp bends in the conductor which could lead to breakage of the conductor at the point of connection to the electrical device. However, such strain reliefs are still capable of bending to a limited degree which, over time and a large number of bends, lead to degradation and breakage of the electrical conductor at the point of connection to the electrical device.
Thus, it would be desirable to provide a swivel apparatus for an electrical device, such as a hand held, bar code scanner, which minimizes degradation or wear on the electrical conductor attached to the scanner caused by bending of the conductor. It would also be desirable to provide a swivel apparatus for a hand held, bar code scanner which is simple in construction and has a low manufacturing cost. It would also be desirable to provide a swivel apparatus for a hand held, bar code scanner which may be adapted for use with many different styles of bar code scanners. Finally, it would be desirable to provide a swivel apparatus which provides strain relief for an electrical conductor attached to an electrical device to minimize sharp bends at the point of connection of the electrical conductor to the electrical device by converting such bending forces to twisting movement of the swivel apparatus and electrical conductor.